Capstan

ABSTRACT

A capstan includes a frame, a reel for reeling a cable and a bolt for supporting the reel on the frame. The stress in the cable gets larger as the strain in the bolt gets larger. A driving device is operable to rotate the reel on the bolt. A strain gauge is attached to the bolt for measuring the strain in the bolt. A control box calculates the stress in the cable based on the strain in the bolt. A display shows the stress in the cable under the control of the control box.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a capstan and, more particularly, to acapstan equipped with a stress indicator.

2. Related Prior Art

Capstans are used to reel cables or chains. However, no capstan isequipped with a stress indicator to the best understanding of theapplicant of the present application. Therefore, the stress in thecables or chains cannot be monitored. Should the stress exceed thedesigned limits of the cables or chains, the cables or chains would verylikely be broken. The broken cables or chains inevitably entail the lossof property. What is worse, the broken cables or chains might causecasualty like whips.

Therefore, the present invention is intended to obviate or at leastalleviate the problems encountered in prior art.

SUMMARY OF INVENTION

According to the present invention, a capstan includes a frame, a reelfor reeling a cable and a bolt for supporting the reel on the frame. Thestress in the cable gets larger as the strain in the bolt gets larger. Adriving device is operable to rotate the reel on the bolt. A straingauge is attached to the bolt for measuring the strain in the bolt. Acontrol box calculates the stress in the cable based on the strain inthe bolt. A display shows the stress in the cable under the control ofthe control box.

An advantage of the capstan according to the present invention is thesecurity of property.

An advantage of the capstan according to the present invention is thesafety of users.

Other advantages and features of the present invention will becomeapparent from the following description referring to the drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of thepreferred embodiment referring to the drawings wherein:

FIG. 1 is a perspective view of a capstan according to the preferredembodiment of the present invention;

FIG. 2 is an exploded view of the capstan shown in FIG. 1;

FIG. 3 is a right side view of the capstan shown in FIG. 1;

FIG. 4 is a perspective view of a cable wound on the capstan shown inFIG. 1;

FIG. 5 is a front view of the cable and capstan shown in FIG. 4; and

FIG. 6 is a front view of the cable and capstan in another position thanshown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, according to the preferred embodiment of thepresent invention, a capstan 10 includes a frame 20, a reel 40, adriving device 30, a shaft 50 and a stress indicator 60.

The frame 20 is a U-shaped element including a first wall 21, a secondwall 22 and a floor on which the walls 21 and 22 are formed. An aperture211 is defined in the first wall 21 corresponding to an aperture 221defined in the second wall 22.

The reel 40 includes a first disc 41, a second disc 42 and a tube 43between the discs 41 and 42. A gear 411 is formed on the first disc 41.The gear 411 is formed with teeth 412. An aperture 421 is defined in thesecond disc 42. A plate 423 is attached to the second disc 42 by twothreaded bolts 422 engaged with two nuts 424. A tunnel 431 is defined inthe tube 43.

Referring to FIG. 3, a bolt 50 is inserted in the apertures 211 and 221and the tunnel 431 so that the reel 40 is rotationally disposed on theframe 20. The bolt 50 is formed with a head 51 at an end and a thread 52at an opposite end. The thread 52 of the bolt 50 is engaged with thethread of a nut 53.

Referring to FIG. 4, a cable 70 is wound on the reel 40. An end of thecable 70 is inserted through the aperture 421 and pressed against thesecond disc 42 by the plate 423.

The driving device 30 includes a shaft 31 formed with a head 34. Theshaft 31 is inserted through the walls 21 and 22. A pinion 32 isdisposed on the shaft 31 and engaged with the gear 411. A rocker 33includes a collar at an end and a grip at an opposite end. The collar ofthe rocker 33 is moved on the shaft 31 between an active position and aneutral position. In the active position, the collar of the rocker 33can rotate the shaft 31. In the neutral position, the collar of therocker 33 cannot rotate the shaft 31. A washer 36 is disposed againstthe head 34. An elastic element 35 is compressed between the washer 36and the collar of the rocker 33 for pushing the collar of the rocker 33to the active position.

Referring to FIG. 6, by operating the rocker 33 in a direction, theshaft 31 is rotated in the same direction. The reel 40 is rotated in anopposite direction due to the engagement of the gear 411 with the pinion32.

The stress indicator 60 includes a strain gauge 62, a control box 61 anda display 611. The strain gauge 62 is attached to the bolt 50. Thecontrol box 61 is attached to the second wall 22. The display 611 isattached to the box 61. The control box 61 contains electronic elementselectrically connected to the strain gauge 62 on one hand andelectrically connected to the display 611 on the other hand.

Referring to FIG. 5, the stress in the cable 70 gets larger as thestrain in the bolt 50 gets larger. The strain gauge 62 detects strain inthe bolt 50 and notifies the control box 61 of the same. Based on thestrain in the bolt 50, the control box 61 calculates the stress in thecable 70. The control box 61 instructs the display 611 to display thestress in the cable 70. A user can maneuver the rocker 33 to reel in thecable 70 while monitoring the stress in the cable 70 on the display 611.The user can decide to stop or continue.

The capstan 10 enables the user to know the stress in the cable 70 forincluding the strain gauge 62 and the display 611. Moreover, the capstan10 enables the user to easily monitor the stress in the cable 70 whilereeling in the cable 70 since the display 611 and the rocker 33 are onthe same side. The user can stop maneuvering the rocker 33 and preventthe rapture of the cable 70 before the stress in the cable 70 reachesits limit. Therefore, the capstan 10 exhibits at least two advantages.Firstly, property is secured. Secondly, the safety of the user isensured.

The present invention has been described via the detailed illustrationof the preferred embodiment. Those skilled in the art can derivevariations from the preferred embodiment without departing from thescope of the present invention. Therefore, the preferred embodimentshall not limit the scope of the present invention defined in theclaims.

1. A capstan comprising: a frame; a reel for reeling a cable; a bolt forsupporting the reel on the frame so that the stress in the cable getslarger as the strain in the bolt gets larger; a driving devicemaneuverable to rotate the reel on the bolt; a strain gauge attached tothe bolt for measuring the strain in the bolt; a control box forcalculating the stress in the cable based on the strain in the bolt; anda display for showing the stress in the cable under the control of thecontrol box.
 2. The capstan according to claim 1 wherein the frame is aU-shaped element.
 3. The capstan according to claim 1 wherein the reelis formed with a gear, and the driving device comprises a shaftrotationally disposed on the frame, a pinion secured to the shaft andengaged with the gear and a rocker maneuverable for rotating the shaft.4. The capstan according to claim 3 wherein the rocker is movablebetween an active position for driving the shaft and a neutral positionfor releasing the shaft.
 5. The capstan according to claim 4 wherein thedriving device comprises an elastic element for pushing the rocker tothe active position.
 6. The capstan according to claim 5 wherein theshaft is formed with a head so that the elastic element is compressedbetween the rocker and the head.
 7. The capstan according to claim 6wherein the driving device comprises a washer located between theelastic element and the head.
 8. The capstan according to claim 1wherein the reel comprise two discs and a tube between the discs.
 9. Thecapstan according to claim 1 wherein one of the discs defines anaperture through which an end of the cable is inserted.
 10. The capstanaccording to claim 9 comprising a plate for pressing the end of thecable against the disc.
 11. The capstan according to claim 10 comprisingthreaded bolts and nuts engaged with the threaded bolts for pressing theplate against the disc.
 12. The capstan according to claim 3 wherein therocker and the display are disposed on a same side of the frame so thata user can observe the while maneuvering the rocker.